Well, it turns out that I don't need the ALDL to check the engine codes as there is a jumper near the ECM that will output the codes for me. The wire is blue and white, and it has a spade terminal with a clear boot connector to plug it into. Checked the codes, and it came back with an error in the VSS. My first thought is that there is a wire loose from the tranny, and short of that I guess that the sensor has gone bad. Anyone else had a code 24 VSS error, and what was the outcome?

1992 Isuzu Rodeo, newly rebuilt 3.1L v6 and rear diff; clear corners, bumper and tails; Aiwa MP3 head unit; Infinity Perfect 10.1 sub; Polk seperates; Sony cross and amps.
Next projects -- New paint, tint, billet grill, nerf bars.